IM 12B6K3-E-E9th Edition

UserManual

Model PR20Retractable fitting forcombined pH/redox electrodes

IM 12B6K3-E-E

IM 12B6K3-E-E

CONTENTS

1. GENERAL 21-1.Description 21-2.Features 21-3.Safety precautions 2

2. UNPACKING AND CHECKING 32-1.Unpacking and inspection 32-2.Mounting location 32-3.Specifications 42-4.Model and codes 52-5.Dimensions 8

3. INSTALLATION AND WIRING 93-1.General 93-2.Accessories 103-3.Preparing the electrode for use 103-4.Mounting the electrode 103-5.Probe insertion 123-6.Adjusting the iinsersion depth 133-7.Wiring 13

4. MAINTENANCE 144-1.General 144-2.Cleaning 144-3.Calibration 154-4.Replacing the electrode 164-5.Replacing the O-rings 164-6.Replacing the cable 174-7.Flush port connections 17

5. EXPLODED VIEW 19

6. SPARE PARTS LIST 20

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1. GENERAL

1-1. DescriptionThe retractable fitting with ball-valveallows a safe insertion and retrac-tion of a combined pH/referenceelectrode while the process isunder pressure. It can be mountedin a variety of positions as long asthe electrode is in an almost verticalposition with the tip pointing down-ward (see fig. 2-1).

The insertion depth can be selectedon site. A minimum insertion depthof 0.2 mtr. into the process liquid isadvised to have a fast temperatureresponse. A special 'memory' ringis provided to remember the posi-tion of the electrode after retraction.To protect any loss of processliquid the mechanism for releasingthe probe is designed to operateonly when the ball-valve is closed.The combined pH/reference elec-trode can be replaced or calibratedeasily. The especially designedcable has integrated leads for thetemperature sensor, shielding andliquid earth. The end is pre-finishedwith cable endings for easy moun-ting to industrial transmitters.

1-2. Features- A safe "through the valve" inser-

tion and retraction design.- Additional safety though a special

designed 'T-bar' locking mecha-nism.

- Maintenance, replacement andcalibration of the electrode withoutinterruption of the process.

- Adjustable insertion depth foroptimal measuring position in theprocess.

- Easy replacement of the electrode.- Improved sealing and damping by

addition O-rings.- Integrated liquid earth and tempe-

rature sensor (Pt100 or Pt1000 toIEC 751 or DIN 43760).

- Simplified installation by optionalball-valves with flanged or taperedconnections.

- Available in two different materialsand two different lengths (0.5 mtr.and 1 mtr.)

1-3. Safety precautionsThe PR20 has been designed togive maximum safety in operation.For optimum safety a flanged ball-valve is recommended.

Yokogawa does not accept anyclaims or penalties on possibledamages or accidents which occur-red by operation of the PR20 fitting.

The installation of the probe is to beimplemented under the local safetyregulations for pressurised vesselsor pipe-lines for retraction or inser-tion. The instructions given in thismanual must be followed exactly.

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Fig. 2.1. Angle of fitting

WarrantyYokogawa Europe B.V. warrantsthat the goods delivered are madefrom new materials to the bestworkmanship available. Malfunctionof any of the delivered goods orparts, can only lead to replacementof the damaged parts. No claimscan be made to damages or acci-dents resulting from the use of thegoods. No claims can be made tothe expected or promised perfor-mance of the goods under any cir-cumstances.

Damaged goods or parts should besent to the local Service organisa-tion for warranty claim purposes.Yokogawa has the right to denywarranty claims after investigationof the data and the materials.

INCORRECT

15º 15º

HORIZONTAL

CORRECT CORRECT

2. UNPACKING AND CHECKING

2-1. Unpacking and inspectionWhen you receive the PR20 retrac-table fitting it is packed in a card-board box. Open the box andcheck that the model code on thefitting is the same as on the pac-king list (see §2-4). The model codewith serial number of the fitting areon an identification plate fixed onthe protection ring.Also check that the options youordered are supplied. These optionsare delivered in separate bags.If you have any problems orquestions, please contact thenearest Yokogawa service centre orsales organisation for assistance.

2-2. Mounting locationThe PR20 fitting is intended to beused for in-line pH measurement.When it is delivered with an optionalball-valve or when it is used in com-bination with a locally purchased 1inch ball-valve, the process doesnot need to be interrupted for main-tenance of the sensor. The locationcan be in a large diameter pipelineor a vessel. The angle of the fittingwith the horizon should not be lessthan 15 degrees (see fig. 2-1).

The pressure- and temperatureratings of the electrode inside thefitting determine the maximumrating of the measurement point.

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2-3. SpecificationsMaterials (wetted parts)

ProbeModel PR20-S : Stainless steel AISI 316Model PR20-T : Titanium

O-ring seals : Viton 70° shoreSilicone rubber 50° shore

Non-wetted : Stainless steel (AISI 316) andparts polyphenylene sulphide (PPS)Process conn. : 11/4" BSP-female (see modelcode for other connections)Insertion length :The dimensional drawing indicates the maximum

insertion length for both specified probe lengths.

Pressure/temperature ratingsStatic conditions : 2 MPa at 20°C, 500 kPa at 125°COperating conditions : max. 500 kPa, max. 100°C

Weight : Approx. 2.5 kg. (SS316 version without ball-valve)

Specification of the optional senorsSC21-AAP26 : 1 to 500 kPa at 0 to 110°C, (pH/ref electrode)SC21-AGP26 : 1 to 500 kPa at 0 to 110°C, (pH/ref electrode)SC21-ALP26 : 1 to 500 kPa at 0 to 110°C, (pH/ref electrode)SC21-AGP24 : 1 to 500 kPa at 0 to 80°C, (pH/ref electrode)SC29-PTP29 : 1 to 500 kPa at 0 to 110°C, (Redox/ref electrode)

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* Note: The insertion depth of the probe is given in the dimensional drawing.

Model Suffix code DescriptionPR20 Retractable fittingMaterial -S Stainless steel AISI 316

-T TitaniumProbe length*) -05 0.5 mtr.

-10 1 mtr.Cable length -05 5 mtr.

-10 10 mtr.Temp. sensor -T1 Pt1000

-T2 Pt100Style *B Style codeAdapters /YYY See separate tableCertificates /M Material certificate 3.1B according to

EN-10-024 (DIN 50049) on wetted partsa/T Test certificate for hydrostatic pressure

test (2 MPa at ambient temperature)Combined /EB SC21-AAP26electrode /EG SC21-AGP24

/EH SC21-AGP25

2-4. Model and codes

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ISO 228/1-G 1

ISO 229/1-G 1 1/4

20(0

.78)

45(1

.77)

ISO 229/1-G 1 1/4

63 (2.55)

65(2

.56)

A B

DR 1 - 11 1/2 NPT acc. ANSI B 1.20.1

Options

Adapter Option code DrawingModel PR20-S PR20-TAdapter only1" BSP-male /SBS /TBS A1" NPT-male /SNS /TNS ADIN flange DN25 PN16 /SDS /TDS B, CANSI flange 1" 150 lbs /SUS /TUS B, C

Adapters and ball-valve1" BSP-female /SBB /TBB A, D1" NPT-female /SNN /TNN A, DDIN flange DN25 PN16 /SDD /TDD B, C, EANSI flange 1" 150 lbs /SUU /TUU B, C, EAdapter with flush portsDIN flange DN25 PN16 /SES /TES F,CANSI flange 1" 150 lbs /SVS /TVS

Adapter with flush ports and ball-valveDIN flange DN25 PN16 /SED /TED F, C, EANSI flange 1" 150 lbs /SVU /TVU F, C, EWeld in adaptersStraight welding /SWRAngled at 15 degrees /SWA

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lk

dD

NW25

Ddkl

ø115ø42.5ø85ø14

ø108ø42.5ø79.2ø15.7

1 inch95 (3.75)

125 (4.9)

65(2

.56)

23(0

.90)

ISO 229/1-G 1 1/4

63 (2.55)

FE

DC

Internal thread (both sides)ISO 228/1-G 1 OR1 - 11 1/2 NPT ACC. ANSI B 1201

Glanges (both sides)DN25-PN10 acc. DIN 2642 or1”-150Lbs acc. ANSI B 16.5 1/8 - 27 NPT vlg. ANSI G 1.20.1

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2-5. Dimensions

ø 48(ø 1.9)

ø 34(ø 1.3)

ø 55(ø 2.16)240

(9.45)

ø 23(ø 0.90)

390 or 890 (15.35 or 35)

550 or 1050 (21.65 or 41.35)

200 or 700(7.9 or 27.5)

DIN 85 (3.35)ANSI: 79.4 (3.125)

125(4.95)

BSP: 275 or 775 max. (10.85 or 30.5)NPT: 265 or 765 max. (10.45 or 30.1)

95 (3.75)

ø 48(ø 1.9)

ø 21(ø 0.83)

mm (inch)

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Fig. 3-1a. Pipe mounting

Fig. 3-1b. Tank mounting

3. INSTALLATION AND WIRING

3-1. GeneralIt is important to have the point ofmeasurement in a location that isrepresenting the process composi-tion. Check whether the specifica-tions of the electrode fulfil the maxi-mum occurring process conditions.The fitting has several optional con-nection possibilities. Check that youreceived the correct size and type.Install the fitting at a convenientlocation for maintenance and calib-ration. For maintenance or calibra-tion the probe will need a space ofabout 2 mtr. for total retraction(depending on probe length andoptional process adapters and/orball-valves). The position of the fit-ting must be within 15 degrees ofthe horizon with the tip pointingdownward (see fig. 2-1). Installationin a bend of a pipe-line is a goodmeasurement position.When inserting the PR20 retracta-ble fitting in a perpendicular positionto the process flow, the flow veloci-ty will put a mechanical force on theprobe. Take care that this force isnot too large. It is recommended tohave the PR20 retractable fittingpositioned at a 45° angle into theprocess stream.

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2. Remove the two O-rings (notused). These O-rings are sup-plied with the electrode and NOTused in the PR20 retractable fit-ting.

3. Mount the separately deliveredO-ring on the connector plug.Push the spacer and the O-ringover the electrode. This is a plas-tic tube + O-ring delivered withthe PR20.

3-4. Mounting the electrode1. Push the cage onto the electrode

(see fig. 3-4.)2. Press the assembly into the

probe.3. Tighten it by turning clock-wise.

Note:The cage fits firmly on the elec-trode, caused by the O-rings ins-ide the cage. The assembly ofelectrode and cage can be tigh-tened until it stops. No tools arenecessary.

IMPORTANT NOTICESBefore the electrode is inserted intothe process, the electrode needs tobe cleaned and calibrated. The cali-bration procedure is normallydescribed in the instruction manualof the pH transmitter. Before thecage is pushed onto the electrode,the stopper should be removed(see Nr. 30 in the exploded view).

ATTENTIONDo not insert the fitting into the pro-cess without the electrode moun-ted! Prevent liquid to come intocontact with the connector plug.Start with the assembly of the elec-trode into the probe and follow theinstructions for the preparation of anew electrode (see §3-3).

3-2. AccessoriesOptional accessories are deliveredseparately. When a ball-valve isordered as an option, this shouldbe mounted to the measuring posi-tion first. When the ball-valve inplace, the process line is secure.

If the ball-valve has a tapered con-nection, it needs to be locked withthe supplied glue. Next the adapterat the other side of the ball-valveneeds to be mounted. This adapterhas 11/4" BSPP-male thread at oneside and matching connection forthe ball-valve at the other side.Mount the adapter on the ball-valveand lock it with the supplied glue.

3-3. Preparing the electrode1. Romove the “wet” pocket.

Squeeze it to let in airRemark:The electrode used with theretractable fitting if suppliedseparately or as an option withthe fitting. The electrode is readyfor immediate use because it isshipped in a 'wet' pocket.

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Unscrewthe pigtail.One will hear clicking.

Move thepigtail

Move theplug-inconnector

Movethe cable

figure 3.3 preparing theelectode for use

Turn thight

Press

figure 3.4 Mounting the electrode in the PR20fitting

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Fig. 3-5. Probe insertion

FIXING SCREW

1

2 3

4

5

2. Pushing the probe into the pro-cess needs a force to overcomethe pressure of the system andthe friction of the damping ringsin the fitting.

3. The locking mechanism can beturned until the probe is firmlyfixed at the measuring position.

4. The memory ring can be fixed atthe actual insertion position. See§3-6 on adjusting the insertiondepth.

3-5. Probe insertion

Insert the probe according to nextprocedure (see also fig. 3-5):1. Position the probe for insertion.2. Turn the T-bar key clockwise3. Open the ball-valve.4. Push the probe into the process.5. Fix the probe by turning the

fixing screw clockwise.

Remarks:1. Turning the T-bar key can

ONLY be done when the valve isclosed. Make sure the probe isfirmly fixed.

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3-6. Adjusting the insertiondepth

The insertion depth of the electrodecan be adjusted to your preference(see fig. 3-6). An insertion depth ofat least 0.2 m is recommended fora fast response of the temperaturesensor. This sensor is locatedabove the combined electrode.When the probe is inserted for 0.2m or more the temperature sensorwill follow the process temperatureaccurate.

The 'memory'ring can be positio-ned at the actual insertion positionof the probe. The "Allan"key, sup-plied with the fitting is used to fixthe 'memory'ring at the desired

fig. 3-6 variable insertion depht

position. The maximum insertiondepth is related to the probe lengthmentioned in the model code of thefitting.

3-7. WiringThe cable used in the PR20 retractable fitting is prepared foreasy connection to pH transmitters.The numbering of the wires isaccordingly to the standard numbe-ring of Yokogawa transmitters.

Remark:To make full use of the capabilitiesof the combined pH/Referenceelectrode, the cooperation withYokogawa pH transmitters is preferred.

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Temperature 11

Temperature 12

Reference 13

Liquid Earth 14

Glass electrode 15

Shield 16

Transparent

Yellow

Red

Black

Black

Blue

1 2 3 4 5

4. MAINTENANCE

4-1. GeneralBefore the combined electrode canbe serviced, the probe with theelectrode should be physicallyseparated from the process. ThePR20 retractable fitting can beretracted from the measuring posi-tion in the maintenance position byfollowing the procedure describedin §4-2.When (optional) flush ports are avai-lable, it is not necessary to disas-semble the probe as indicated initems [4] and [5] of fig. 4-2. Theflush ports enable you to cleanand/or calibrate the electrode in theposition shown in [3] of fig. 4-2.For replacement of the electrodethe probe has to be disassembled.

4-2. CleaningRetract the probe from the processfor cleaning the electrode (see alsofig. 4-2):1. Release the fixing screw.2. Pull out the probe.3. Close the ball-valve (*).4. Unlock the probe.5. Take out the probe.* If flush ports are available the sen-sor can be flushed with cleaningliquid.

ATTENTION:1. Stand clear when releasing

the fixing screw! Due to theprocess pressure the probecan be pressed out.

2. The T-bar can only be opera-ted when the ball-valve is clo-sed. Make sure it is closedcompletely.

3. The friction of the O-rings willslow down the probe when it isretracted.

4. When the sensitivity of the elec-trode has decreased or theresponse has slowed down, theelectrode should be cleaned.

Fig. 4.2. Exsertion of the probe

Fig. 4.1. Cable markers

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If cleaning with hot water is notwater is not sufficient, more aggres-sive water based agents should beused.- Deposits of limes, hydroxides or

carbonates can be removed byimmersing the electrode in a solu-tion containing diluted hydrochlo-ric acid. Afterwards rinse the elec-trode with water.

- Deposits of oil and fat can beremoved with hot water in con-junction with a detergent. Whenthe results are unsatisfactory amild (carbonate based) abrasivecan be used.

- Protein (albuminous) depositsshould be removed with a proteinenzymatic solution. For instance asolution containing 8.5 ml con-centrated hydrochloric acid and10 gr pepsin in 1 litre water.

ATTENTIONAvoid using non-polar solvents liketri-chloro ethylene, toluene or hexa-ne. Even cleaning with ethanol oracetone is not recommended.These solvents will break up thegel-layer on the glass bulb andafterwards needs to remain soakedin water for at least 12 hours beforefunctioning normal.

The PTFE diaphragm of the combi-ned electrode can sometimes beregenerated by putting it in hot (60to 80°C) 1 molar Potassium chlori-de (KCl) solution and letting it coolto room temperature.After cleaning the probe is re-inser-ted into the process by followingthe reverse procedure (see §3-5).

4-3. CalibrationIt is recommended to start calibra-tion with a clean electrode. Alwayscalibrate a new electrode.

With the electrode connected to thetransmitter a calibration can takeplace. Check the appropriate chap-ters in the instruction manual of thepH transmitter for details.To take out the probe for cleaningthe electrode, follow the proceduredescribed in §4-2.

General procedure for calibra-tionTo calibrate a pH transmitter twobuffer solutions with known pHvalue are required. It is recommen-ded that one buffer solution has avalue near pH 7.Depending on the liquid to bemeasured the second buffer solu-tion should either be in the acidic orbase area. Normally the buffers pH4.01 or 9.22 are used.

Generally the procedure for calibra-tion is as follows:- Clean the electrode - Rinse the electrode with water- Immerse the electrode in the first

buffer solution (pH 7)- Adjust the asymmetry setting of

the transmitter for reading aknown value

- Rinse the electrode with water- Immerse the electrode in the

second buffer (pH 4 or pH 9)- Adjust the slope setting of the

transmitter for reading a knownvalue

- Rinse the electrode with water.

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Fig. 4-3. Replacing the O-rings

1

2

3

click

1 2 3 4

180º

pin

slot

During calibration the temperaturecompensation should be active. It isadvised to, calibrate with buffersolutions at a temperature near theprocess temperature.

After calibration the probe withelectrode is replaced following theprocedure in §3-5.

4-4. Replacing the electrodeStart with removing the probe byfollowing the procedure describedin §4-2.1 Turn the cage anti-clockwise2 Pull out the assembly.3 Take off the cage, spacer

and O-ring.

Now the electrode can be exchan-ged for a new one. See §3-3 forpreparation of the new electrode.

4-5. Replacing the O-ringsThe drawing (see fig. 4-3) showsthe position of the sealing O-ringson the outside and the inside of thecage. Exchange them when rene-wing the electrode.The O-rings are available as spareparts. Refer to the exploded viewfor the numbers.

The protection cage can be splitinto two parts. The threaded part[24] contains five O-rings. Three O-rings on the outside [26 and 27]

2726

28

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Fig. 4-4. Flush ports

can be replaced by new ones easi-ly.Two O-rings [28] are located insidethe protection cage and need to betaken out, using a pointed tweezersor needle. This will damage thematerial, so the rings cannot beused again.Put in new O-rings without usingmechanical tools, preferably withyour fingers. Fold the O-ring beforeinserting it into the cage. It will popinto place easily.

The single O-ring [14] at the con-nector is delivered with the fittingand seals the plug for moisture.Replace it when it is damaged orwhen you think it is necessary.

4-6. Replacing the cableFollow the procedures for retractionand disassembling from the pre-vious chapters (see §4-1 to 4-5).After removing the electrode thecable can be removed by disas-sembling the cable gland [2] asindicated in the exploded view inchapter 5.Then the cable [1] can be removedand a new one can be inserted.Reassemble the cable gland ontothe cable and tighten it.

4-7. Flush port connectionsThe PR20 retractable fitting can beequipped with (optional) flush portson the flanged adapters. This ena-bles you to flush the electrode withwater or cleaning agent when theprobe is in the fully retracted posi-tion (see fig. 4-4).There are four (4) flush ports availa-ble. They can be used according toyour preferences. The flush portsare tapered 1/8" NPT-female forsmall diameter connectors.It is also possible to make buffersolution flow through and calibratethe combined electrode withoutdismounting the probe.

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5. EXPLODED VIEW1 Cable with plug-in connector2 Cable gland3 Outer tube4 Positioning ring5 "Allan" screw6 Main fixing screw7 Squeezing ring (2pcs)8 Clamping ring9 Bushing (2pcs)10 O-rings (2pcs), Viton 70° shore (20.2x3.5)11 Fixing screws (2 pcs)12 Protection ring13 Inner tube14 O-ring Viton 70° shore (12x1)15 T-bar with key16 Nut17 Fixing screws (2 pcs)18 Chamber19 O-ring Viton 70° shore (29.7 x 3.5)20 Adapter (optional)21 Ball-valve (optional)22 Combined pH/reference electrode 23 Spacer24 Electrode holder25 Protection sleeve26 O-rings (2 pcs), Viton 70° shore (15.6 x 1.78)27 O-ring, Viton 70° shore (17.12 x 2.62)28 O-rings (2 pcs), Viton 70° shore (11 x 3)29 O-ring EPDM 70° shore (11.92 x 2.62)30 Stopper (remove)

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6. SPARE PARTS LISTK1520AX O-ring set 1 26, 27, 28, 14K1520AY O-ring set 2 10, 19 K1520KA Holder set (AISI 316) 24, 25, 26, 27, 28K1520KE Holder set (titanium) 24, 25, 26, 27, 28K1520AW Gland set 2K1520LP Cable 5 m (Pt100) 1K1520LQ Cable 5 m (Pt1000) 1K1520LS Cable 10 m (Pt100) 1K1520LT Cable 10 m (Pt1000) 1K1520AZ Spacer 23K1520KD Clamp ring 8K1520KC Fixing screw 6K1520KF Positioning ring 4, 5K1520TA Clamping set 7, 8, 9K1520TF Nut 16K1520TK Key 15K1520TN Outer tube 3K1520UB Clamping set (Titanium) 7, 8, 9K1520UH Outer tube 1.0 m (SS) 3K1520UF Outer tube 0.5 m (Ti) 3K1520UJ Outer tube 1.0 m (Ti) 3

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IM 12B6K3-E-E 09-510 (A) QSubject to change without notice Printed in The NetherlandsCopyright©

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